One gene that has received a fair amount of attention is known as monoamine oxydase A (MAOA) and codes for an enzyme (also called MAOA) involved with the metabolism of key neurotransmitters involved with emotion and behavior, specifically serotonin, norepinephrine, and dopamine. A variant of this gene reduces MAOA enzyme activity and is more common in antisocial individuals than in controls. It is likely, however, that this gene codes for impulsivity rather than antisocial behavior per se. Another gene, called-G1438A, is related to the 5HT2A subtype of the serotonin system. One variant (or polymorphism) of this gene, known as the G-allelle, is associated with increased rule breaking in adolescent boys, as shown in a 2009 study by S. Alexandra Burt. The other variant, known as the A-allelle, is associated with lower levels of rule breaking, and incidentally, lower levels of popularity with peers. In other words, boys with the G-allele were both bigger rule breakers and more popular.
Because of the criminal nature of the drug industry, competition between rival drug dealers is often a horribly violent affair, resulting in countless drug-related deaths. Some analysts believe that drugs should be made legal in order to reduce crime. Others believe legalizing drugs would only i2 increase drug addiction (iStock).